1. Technical Field
The present application relates to a container filling plant for filling containers, such as demijohns and kegs, which filling plant has filler elements for filling of large volume containers with a liquid product, and method therefor.
2. Background Information
Background information is for informational purposes only and does not necessarily admit that subsequently mentioned information and publications are prior art.
In the beverage industry, but also in other branches of industry, very often liquids, for example beverages, on which oxygen, usually atmospheric oxygen, has a damaging effect, have to be filled.
Thus, if it is absorbed by the liquid, the oxygen contained in the ambient air can have a negative influence, for example, with regard to shelf life, color, applicability, digestibility and/or taste.
Purely to simplify the comprehensibility of the present application, but in no way limiting the scope of protection of the present application, beverages are referred to exclusively below, said beverages being representative of all or virtually all comparable liquids that are sensitive to oxygen.
On account of the sensitivity to oxygen of numerous beverages, great efforts are made to keep the oxygen contained in the ambient air as far as possible away from the beverage to be filled during the production process.
One of such measures, for example, is to rinse the interior space of the container to be filled before the actual filling procedure, for example several times with an oxygen-free or low-oxygen process gas in order to remove the ambient air that is present there, and consequently also the atmospheric oxygen contained in said air, out of the container.
Some methods involve rinsing or flushing the container interior itself. Thus, the container interior is impinged upon several times with negative pressure, and then is brought back once again by the supplying of an oxygen-free process gas, for example CO2, to a higher pressure, thereby clearly reducing the oxygen content in the container interior.
In the case of another method, which is used usually with unstable containers, a so-called rinsing or flushing tube is first of all introduced into the container. An oxygen-free process gas, for example CO2, is then introduced through said rinsing or flushing tube into the container, said process gas displacing out of the container the ambient air situated inside the container. In this case, the container can also be impinged upon with a slight negative pressure or overpressure, the corresponding pressures being matched to the low stability of the container.
At least one possible embodiment of the present application relates to a device that operates as follows: the rinsing or flushing tube, positioned centrally relative to the filler element axis, is moved into the upper region of the container and is impinged upon with oxygen-free process gas. The oxygen-free process gas flowing out of the rinsing or flushing tube, after leaving the rinsing or flushing tube, flows, for instance, in the direction of the container bottom and in doing so displaces the gas present in the container, for example ambient air, in the direction of the container mouth where it can escape out of the container through a gas path provided at that location.
Once the rinsing or flushing process has been completed, the rinsing or flushing tube is moved out of the container, whereupon the liquid valve is opened, leading directly to the liquid product flowing into the container.
In at least one possible embodiment of the present application, the liquid product is set in rotation by a swirling body that is positioned inside the liquid path, thereby creating centrifugal forces which move or guide the liquid product to the inside wall of the container, thereby forming a liquid film that abuts against the inside wall of the container and flows into the container. Once the desired fill level has been obtained, the liquid valve is closed.
A disadvantage of such a method, among other things, is the large surface that the liquid flowing off the inside wall of the container has, as any oxygen still possibly remaining inside the container could be absorbed by said large surface. The larger the free surface and the greater the exposure time, the greater the amount of the oxygen possibly absorbed by the liquid flowing in.
Likewise, the small depth of insertion of the rinsing or flushing tube is disadvantageous as the oxygen-free process gas flows into the oxygenated gas there quasi midstream, thereby not resulting in an optimum, loss-free gas exchange.
With regard to the residual oxygen content and the operating efficiency, some methods and devices are stretched to the limit when the containers to be processed or filled exceed a certain volume.
This is also usually because some devices do not allow for the rinsing or flushing tube to be inserted far enough into the container in order to drive the ambient air in a targeted manner from one end of the container, namely the container bottom, in the direction of the other end of the container, namely the container mouth.
Another reason is that some filler elements, provided with a rinsing or flushing tube, operate exclusively according to the method of diverting the liquid to the inside walls of the container, which implies that as the diameter of the container increases so does the surface of the liquid flowing in. In addition, the greater container height causes the liquid to be exposed for longer. Both factors promote increased oxygen absorption of the liquid.